Spatiotemporal changes and driving factors of vegetation in 14 different climatic regions in the global from 1981 to 2018

Abstract

Vegetation change affects global ecology and conservation, energy balance, and climate change. Analyses of the vegetation driving factors in different global climate regions and the differences in their changes are of great significance to global change research. In this paper, based on the vegetation leaf area index (LAI) and driver datasets, we studied the vegetation drivers and their changes in 14 different climate zones around the world from 1981 to 2018. The results showed that (1) Vegetation changes were sensitive to precipitation and evapotranspiration in arid climate zones and to temperature and soil temperature in cold climate zones. In the tundra climate zone, the sensitivity of vegetation change to temperature was higher than that to precipitation and evapotranspiration. (2) Soil moisture has the highest contribution rate to vegetation change, and the areas with absolute contribution rates over 60% account for 50.26% of the total area of global vegetation cover. The areas with high contributions of temperature and soil temperature to the LAI are mainly distributed in the Northern Hemisphere, which indicates that temperature has a high contribution to vegetation change in low-temperature environments. (3) The areas with significant increasing trends for the global vegetation LAIs accounted for approximately 15.32% of the total global vegetation cover (slope ≥ 0.01), which are mainly located in equatorial savannahs with dry winters, warm temperate climates with dry winters, and warm temperate climates with fully humid climatic zones. (4) The LAIs were dominated by medium-high fluctuations and sustainable increasing changes, which accounted for 61.27% and 69.34% of the total global vegetation cover area, respectively. This study contributes to our understanding of the role of long-term changes in vegetation cover and its climate-driven mechanisms in global change, and provides technical support for global ecology and conservation.